Best theme park and water park for 3 and 6 year old?

[Ricepops]

I'm planning a weekend away in June to take my DC to a theme park and indoor water park. Does anyone have any suggestions? They love fairground rides, but at the same time aren't very tall for their ages. Would there be anything to do at Legoland for the 3 year old? What about water parks - are there any near Peppa Pig World? I couldn't really find anything decent looking except for Alton Towers splash landings. If we go to Alton Towers, is CBeebies land any good?

We have been to Alton Towers / Cbeebies quite a few times!! DD is 9 now so she also gets to experience the bigger rides. Cbeebiesland is amazing but you have to pay full "Alton Towers" ticket price so if you're not bothered about the cost I'd highly recommend it. There's a new themed area too just opened this year "The World of David Walliams" with some new kids rides etc. The water park is a bit cold in my opinion considering it's mainly indoors, but the kids love it. It's around £50 for a family of 4 so again if you don't mind the cost it's a fun few hours.

Legoland is perfect for their ages. I'm pretty sure (although it was over 7 years the last time we went, so need someone else to confirm) that they had a splashpad area there.
Alton towers/splash landings/cbeebies land is good too. We stayed in the hotel. They put on fun entertainers for the dc in the evening. There's also a mini sealife centre there.

Paultons (Peppa pig world) is excellent and has two rather good outdoor splash zones which I found more than enough! Weather was mediocre but the kids still had fun.

Center parcs at Longleat, ticks your box for water park and the safari park is next door.

I highly recommend Gulliver’s Kingdom and Sundown Adventure Park. They are pretty no-frills but my daughter and the other children we went with loved both. Ages ranged from 2-6 at the time. Lots cheaper than CBeebies/Peppa Pig Land and far fewer queues.

I second paultons. Loads for a 3 and 6 year old to do! And 2 splash areas.

Twin lakes Melton Mowbray, small but great for little ones